Release 4.11 drivers/staging/fwserial/dma_fifo.c
/*
* DMA-able FIFO implementation
*
* Copyright (C) 2012 Peter Hurley <peter@hurleysoftware.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/bug.h>
#include "dma_fifo.h"
#ifdef DEBUG_TRACING
#define df_trace(s, args...) pr_debug(s, ##args)
#else
#define df_trace(s, args...)
#endif
#define FAIL(fifo, condition, format...) ({ \
fifo->corrupt = !!(condition); \
WARN(fifo->corrupt, format); \
})
/*
* private helper fn to determine if check is in open interval (lo,hi)
*/
static bool addr_check(unsigned int check, unsigned int lo, unsigned int hi)
{
return check - (lo + 1) < (hi - 1) - lo;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 32 | 91.43% | 1 | 50.00% |
| Dominique van den Broeck | 3 | 8.57% | 1 | 50.00% |
| Total | 35 | 100.00% | 2 | 100.00% |
/**
* dma_fifo_init: initialize the fifo to a valid but inoperative state
* @fifo: address of in-place "struct dma_fifo" object
*/
void dma_fifo_init(struct dma_fifo *fifo)
{
memset(fifo, 0, sizeof(*fifo));
INIT_LIST_HEAD(&fifo->pending);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 31 | 100.00% | 1 | 100.00% |
| Total | 31 | 100.00% | 1 | 100.00% |
/**
* dma_fifo_alloc - initialize and allocate dma_fifo
* @fifo: address of in-place "struct dma_fifo" object
* @size: 'apparent' size, in bytes, of fifo
* @align: dma alignment to maintain (should be at least cpu cache alignment),
* must be power of 2
* @tx_limit: maximum # of bytes transmissible per dma (rounded down to
* multiple of alignment, but at least align size)
* @open_limit: maximum # of outstanding dma transactions allowed
* @gfp_mask: get_free_pages mask, passed to kmalloc()
*
* The 'apparent' size will be rounded up to next greater aligned size.
* Returns 0 if no error, otherwise an error code
*/
int dma_fifo_alloc(struct dma_fifo *fifo, int size, unsigned int align,
int tx_limit, int open_limit, gfp_t gfp_mask)
{
int capacity;
if (!is_power_of_2(align) || size < 0)
return -EINVAL;
size = round_up(size, align);
capacity = size + align * open_limit + align * DMA_FIFO_GUARD;
fifo->data = kmalloc(capacity, gfp_mask);
if (!fifo->data)
return -ENOMEM;
fifo->in = 0;
fifo->out = 0;
fifo->done = 0;
fifo->size = size;
fifo->avail = size;
fifo->align = align;
fifo->tx_limit = max_t(int, round_down(tx_limit, align), align);
fifo->open = 0;
fifo->open_limit = open_limit;
fifo->guard = size + align * open_limit;
fifo->capacity = capacity;
fifo->corrupt = 0;
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 178 | 99.44% | 1 | 50.00% |
| Dominique van den Broeck | 1 | 0.56% | 1 | 50.00% |
| Total | 179 | 100.00% | 2 | 100.00% |
/**
* dma_fifo_free - frees the fifo
* @fifo: address of in-place "struct dma_fifo" to free
*
* Also reinits the fifo to a valid but inoperative state. This
* allows the fifo to be reused with a different target requiring
* different fifo parameters.
*/
void dma_fifo_free(struct dma_fifo *fifo)
{
struct dma_pending *pending, *next;
if (!fifo->data)
return;
list_for_each_entry_safe(pending, next, &fifo->pending, link)
list_del_init(&pending->link);
kfree(fifo->data);
fifo->data = NULL;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 56 | 98.25% | 1 | 50.00% |
| Christian Colic | 1 | 1.75% | 1 | 50.00% |
| Total | 57 | 100.00% | 2 | 100.00% |
/**
* dma_fifo_reset - dumps the fifo contents and reinits for reuse
* @fifo: address of in-place "struct dma_fifo" to reset
*/
void dma_fifo_reset(struct dma_fifo *fifo)
{
struct dma_pending *pending, *next;
if (!fifo->data)
return;
list_for_each_entry_safe(pending, next, &fifo->pending, link)
list_del_init(&pending->link);
fifo->in = 0;
fifo->out = 0;
fifo->done = 0;
fifo->avail = fifo->size;
fifo->open = 0;
fifo->corrupt = 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 81 | 98.78% | 1 | 50.00% |
| Christian Colic | 1 | 1.22% | 1 | 50.00% |
| Total | 82 | 100.00% | 2 | 100.00% |
/**
* dma_fifo_in - copies data into the fifo
* @fifo: address of in-place "struct dma_fifo" to write to
* @src: buffer to copy from
* @n: # of bytes to copy
*
* Returns the # of bytes actually copied, which can be less than requested if
* the fifo becomes full. If < 0, return is error code.
*/
int dma_fifo_in(struct dma_fifo *fifo, const void *src, int n)
{
int ofs, l;
if (!fifo->data)
return -ENOENT;
if (fifo->corrupt)
return -ENXIO;
if (n > fifo->avail)
n = fifo->avail;
if (n <= 0)
return 0;
ofs = fifo->in % fifo->capacity;
l = min(n, fifo->capacity - ofs);
memcpy(fifo->data + ofs, src, l);
memcpy(fifo->data, src + l, n - l);
if (FAIL(fifo, addr_check(fifo->done, fifo->in, fifo->in + n) ||
fifo->avail < n,
"fifo corrupt: in:%u out:%u done:%u n:%d avail:%d",
fifo->in, fifo->out, fifo->done, n, fifo->avail))
return -ENXIO;
fifo->in += n;
fifo->avail -= n;
df_trace("in:%u out:%u done:%u n:%d avail:%d", fifo->in, fifo->out,
fifo->done, n, fifo->avail);
return n;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 209 | 99.52% | 1 | 50.00% |
| Christian Colic | 1 | 0.48% | 1 | 50.00% |
| Total | 210 | 100.00% | 2 | 100.00% |
/**
* dma_fifo_out_pend - gets address/len of next avail read and marks as pended
* @fifo: address of in-place "struct dma_fifo" to read from
* @pended: address of structure to fill with read address/len
* The data/len fields will be NULL/0 if no dma is pended.
*
* Returns the # of used bytes remaining in fifo (ie, if > 0, more data
* remains in the fifo that was not pended). If < 0, return is error code.
*/
int dma_fifo_out_pend(struct dma_fifo *fifo, struct dma_pending *pended)
{
unsigned int len, n, ofs, l, limit;
if (!fifo->data)
return -ENOENT;
if (fifo->corrupt)
return -ENXIO;
pended->len = 0;
pended->data = NULL;
pended->out = fifo->out;
len = fifo->in - fifo->out;
if (!len)
return -ENODATA;
if (fifo->open == fifo->open_limit)
return -EAGAIN;
n = len;
ofs = fifo->out % fifo->capacity;
l = fifo->capacity - ofs;
limit = min_t(unsigned int, l, fifo->tx_limit);
if (n > limit) {
n = limit;
fifo->out += limit;
} else if (ofs + n > fifo->guard) {
fifo->out += l;
fifo->in = fifo->out;
} else {
fifo->out += round_up(n, fifo->align);
fifo->in = fifo->out;
}
df_trace("in: %u out: %u done: %u n: %d len: %u avail: %d", fifo->in,
fifo->out, fifo->done, n, len, fifo->avail);
pended->len = n;
pended->data = fifo->data + ofs;
pended->next = fifo->out;
list_add_tail(&pended->link, &fifo->pending);
++fifo->open;
if (FAIL(fifo, fifo->open > fifo->open_limit,
"past open limit:%d (limit:%d)",
fifo->open, fifo->open_limit))
return -ENXIO;
if (FAIL(fifo, fifo->out & (fifo->align - 1),
"fifo out unaligned:%u (align:%u)",
fifo->out, fifo->align))
return -ENXIO;
return len - n;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 332 | 98.52% | 1 | 33.33% |
| Dominique van den Broeck | 4 | 1.19% | 1 | 33.33% |
| Christian Colic | 1 | 0.30% | 1 | 33.33% |
| Total | 337 | 100.00% | 3 | 100.00% |
/**
* dma_fifo_out_complete - marks pended dma as completed
* @fifo: address of in-place "struct dma_fifo" which was read from
* @complete: address of structure for previously pended dma to mark completed
*/
int dma_fifo_out_complete(struct dma_fifo *fifo, struct dma_pending *complete)
{
struct dma_pending *pending, *next, *tmp;
if (!fifo->data)
return -ENOENT;
if (fifo->corrupt)
return -ENXIO;
if (list_empty(&fifo->pending) && fifo->open == 0)
return -EINVAL;
if (FAIL(fifo, list_empty(&fifo->pending) != (fifo->open == 0),
"pending list disagrees with open count:%d",
fifo->open))
return -ENXIO;
tmp = complete->data;
*tmp = *complete;
list_replace(&complete->link, &tmp->link);
dp_mark_completed(tmp);
/* Only update the fifo in the original pended order */
list_for_each_entry_safe(pending, next, &fifo->pending, link) {
if (!dp_is_completed(pending)) {
df_trace("still pending: saved out: %u len: %d",
pending->out, pending->len);
break;
}
if (FAIL(fifo, pending->out != fifo->done ||
addr_check(fifo->in, fifo->done, pending->next),
"in:%u out:%u done:%u saved:%u next:%u",
fifo->in, fifo->out, fifo->done, pending->out,
pending->next))
return -ENXIO;
list_del_init(&pending->link);
fifo->done = pending->next;
fifo->avail += pending->len;
--fifo->open;
df_trace("in: %u out: %u done: %u len: %u avail: %d", fifo->in,
fifo->out, fifo->done, pending->len, fifo->avail);
}
if (FAIL(fifo, fifo->open < 0, "open dma:%d < 0", fifo->open))
return -ENXIO;
if (FAIL(fifo, fifo->avail > fifo->size, "fifo avail:%d > size:%d",
fifo->avail, fifo->size))
return -ENXIO;
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 331 | 99.70% | 1 | 50.00% |
| Christian Colic | 1 | 0.30% | 1 | 50.00% |
| Total | 332 | 100.00% | 2 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Peter Hurley | 1310 | 98.87% | 2 | 33.33% |
| Dominique van den Broeck | 9 | 0.68% | 2 | 33.33% |
| Christian Colic | 5 | 0.38% | 1 | 16.67% |
| Carlos E. Garcia | 1 | 0.08% | 1 | 16.67% |
| Total | 1325 | 100.00% | 6 | 100.00% |
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